WandbLogger doesn't format config correctly

Nobody has claimed this yet.

### Bug description

**Summary**: `WandbLogger(config=config)` does not provide the same behavior as `wandb.init(config=config)` in recent versions of pytorch-lightning

**Explanation**:

Passing `config` into `wandb.init` is supposed to create a nicely formatted config in WandB
Example:
`wandb.init(config={'key1': {'key2': 'value'}})`
The Run Overview in wandb looks like this:

A more complicated example of a nested config:

In this WandB run, the keys are logged and searchable as e.g. `model.pool.0` (with corresponding value `4`)

However, this is what it looks like when you run
`pytorch_lightning.loggers.WandbLogger(config={'test_key': {'key2': 'test_value'}})` (which is supposed to pass the `config` entry straight through to `wandb.init`)

Note that the keys are no longer nested and there's only one level of hierarchy where the values are massive dictionaries. Instead of the WandB config having a key of `test_key.key2` with value of `test_value`, there is only a key of `test_key` with a value of `{'key2': 'test_value'}`.

### What version are you seeing the problem on?

v2_0

**Note**: I have used older versions of pytorch-lightning that do not have this issue. I'm not sure if it is a regression and have not had time to bisect.

### How to reproduce the bug

```python
See above
```

### Error messages and logs

```
# Error messages and logs here please
```

### Environment

❯ python collect_env_details.py

Current environment

* CUDA:
- GPU:
- NVIDIA A100-SXM4-40GB
- NVIDIA A100-SXM4-40GB
- NVIDIA A100-SXM4-40GB
- NVIDIA A100-SXM4-40GB
- NVIDIA A100-SXM4-40GB
- NVIDIA A100-SXM4-40GB
- NVIDIA A100-SXM4-40GB
- NVIDIA A100-SXM4-40GB
- NVIDIA A100-SXM4-40GB
- NVIDIA A100-SXM4-40GB
- NVIDIA A100-SXM4-40GB
- NVIDIA A100-SXM4-40GB
- NVIDIA A100-SXM4-40GB
- NVIDIA A100-SXM4-40GB
- NVIDIA A100-SXM4-40GB
- NVIDIA A100-SXM4-40GB
- available: True
- version: 12.1
* Lightning:
- lightning-utilities: 0.8.0
- pytorch-fast-transformers: 0.4.0
- pytorch-lightning: 2.0.1.post0
- pytorch-quantization: 2.1.2
- torch: 2.0.0a0+1767026
- torch-tensorrt: 1.4.0.dev0
- torchaudio: 2.0.1+3b40834
- torchmetrics: 0.11.4
- torchtext: 0.13.0a0+fae8e8c
- torchvision: 0.15.0a0
* Packages:
- absl-py: 1.4.0
- accelerate: 0.18.0
- aiohttp: 3.8.4
- aiosignal: 1.3.1
- alembic: 1.10.3
- antlr4-python3-runtime: 4.9.3
- apex: 0.1
- appdirs: 1.4.4
- argcomplete: 3.0.5
- argon2-cffi: 21.3.0
- argon2-cffi-bindings: 21.2.0
- asttokens: 2.2.1
- astunparse: 1.6.3
- async-timeout: 4.0.2
- attrs: 22.2.0
- audioread: 3.0.0
- autopage: 0.5.1
- backcall: 0.2.0
- beautifulsoup4: 4.11.2
- bleach: 6.0.0
- blessed: 1.20.0
- blis: 0.7.9
- boto: 2.49.0
- cachetools: 5.3.0
- catalogue: 2.0.8
- cauchy-mult: 0.1
- certifi: 2022.12.7
- cffi: 1.15.1
- charset-normalizer: 3.1.0
- click: 8.1.3
- cliff: 4.2.0
- cloudpickle: 2.2.1
- cmaes: 0.9.1
- cmake: 3.24.1.1
- cmd2: 2.4.3
- colorlog: 6.7.0
- comm: 0.1.2
- confection: 0.0.4
- contourpy: 1.0.7
- crcmod: 1.7
- cryptography: 40.0.2
- cubinlinker: 0.2.2+2.g4de3e99
- cuda-python: 12.1.0rc5+1.gc7fd38c.dirty
- cudf: 23.2.0
- cugraph: 23.2.0
- cugraph-dgl: 23.2.0
- cugraph-service-client: 23.2.0
- cugraph-service-server: 23.2.0
- cuml: 23.2.0
- cupy-cuda12x: 12.0.0b3
- cycler: 0.11.0
- cymem: 2.0.7
- cython: 0.29.33
- dask: 2023.1.1
- dask-cuda: 23.2.0
- dask-cudf: 23.2.0
- datasets: 2.11.0
- debugpy: 1.6.6
- decorator: 5.1.1
- deepspeed: 0.9.1
- defusedxml: 0.7.1
- dill: 0.3.6
- distributed: 2023.1.1
- docker-pycreds: 0.4.0
- docutils: 0.19
- dropout-layer-norm: 0.1
- eeghdf: 0.2.4
- einops: 0.6.1
- en-core-web-sm: 3.5.0
- exceptiongroup: 1.1.1
- execnet: 1.9.0
- executing: 1.2.0
- expecttest: 0.1.3
- fasteners: 0.18
- fastjsonschema: 2.16.3
- fastrlock: 0.8.1
- fftconv: 0.1
- filelock: 3.10.0
- flash-attn: 1.0.3.post0
- fonttools: 4.38.0
- frozenlist: 1.3.3
- fsspec: 2023.1.0
- ft-attention: 0.1
- fused-dense-lib: 0.0.0
- future: 0.18.3
- fvcore: 0.1.5.post20221221
- gast: 0.4.0
- gcs-oauth2-boto-plugin: 3.0
- gdown: 4.7.1
- gitdb: 4.0.10
- gitpython: 3.1.31
- google-apitools: 0.5.32
- google-auth: 2.16.2
- google-auth-oauthlib: 0.4.6
- google-reauth: 0.1.1
- gpustat: 1.1
- graphsurgeon: 0.4.6
- greenlet: 2.0.2
- grpcio: 1.51.3
- gsutil: 5.23
- h5py: 3.8.0
- heapdict: 1.0.1
- hjson: 3.1.0
- httplib2: 0.20.4
- huggingface-hub: 0.13.4
- hydra-colorlog: 1.2.0
- hydra-core: 1.3.2
- hydra-optuna-sweeper: 1.2.0
- hypothesis: 5.35.1
- idna: 3.4
- importlib-metadata: 6.0.0
- importlib-resources: 5.12.0
- iniconfig: 2.0.0
- intel-openmp: 2021.4.0
- iopath: 0.1.10
- ipdb: 0.13.13
- ipykernel: 6.21.3
- ipython: 8.11.0
- ipython-genutils: 0.2.0
- ipywidgets: 8.0.6
- jaraco.classes: 3.2.3
- jedi: 0.18.2
- jeepney: 0.8.0
- jinja2: 3.1.2
- joblib: 1.2.0
- json5: 0.9.11
- jsonschema: 4.17.3
- jupyter: 1.0.0
- jupyter-client: 8.0.3
- jupyter-console: 6.6.3
- jupyter-core: 5.2.0
- jupyter-tensorboard: 0.2.0
- jupyterlab: 2.3.2
- jupyterlab-pygments: 0.2.2
- jupyterlab-server: 1.2.0
- jupyterlab-widgets: 3.0.7
- jupytext: 1.14.5
- keopscore: 2.1.2
- keyring: 23.13.1
- kiwisolver: 1.4.4
- langcodes: 3.3.0
- librosa: 0.9.2
- lightning-utilities: 0.8.0
- lit: 15.0.7
- llvmlite: 0.39.1
- locket: 1.0.0
- mako: 1.2.4
- markdown: 3.4.1
- markdown-it-py: 2.2.0
- markupsafe: 2.1.2
- matplotlib: 3.7.0
- matplotlib-inline: 0.1.6
- mdit-py-plugins: 0.3.5
- mdurl: 0.1.2
- mistune: 2.0.5
- mkl: 2021.1.1
- mkl-devel: 2021.1.1
- mkl-include: 2021.1.1
- mlperf-logging: 2.1.0
- mock: 5.0.1
- monotonic: 1.6
- more-itertools: 9.1.0
- mpmath: 1.3.0
- msgpack: 1.0.4
- multidict: 6.0.4
- multiprocess: 0.70.14
- munch: 2.5.0
- murmurhash: 1.0.9
- nbclient: 0.7.2
- nbconvert: 7.2.10
- nbformat: 5.7.3
- nest-asyncio: 1.5.6
- networkx: 2.6.3
- ninja: 1.11.1
- notebook: 6.4.10
- numba: 0.56.4+1.g9a03de713
- numpy: 1.22.2
- nvidia-dali-cuda110: 1.23.0
- nvidia-ml-py: 11.525.112
- nvidia-pyindex: 1.0.9
- nvitop: 1.1.2
- nvtx: 0.2.5
- oauth2client: 4.1.3
- oauthlib: 3.2.2
- omegaconf: 2.3.0
- onnx: 1.13.0
- opencv: 4.6.0
- opt-einsum: 3.3.0
- optuna: 2.10.1
- packaging: 23.0
- pandas: 1.5.2
- pandocfilters: 1.5.0
- parso: 0.8.3
- partd: 1.3.0
- pathtools: 0.1.2
- pathy: 0.10.1
- pbr: 5.11.1
- pexpect: 4.8.0
- pickleshare: 0.7.5
- pillow: 9.2.0
- pip: 21.2.4
- pkginfo: 1.9.6
- pkgutil-resolve-name: 1.3.10
- platformdirs: 3.1.1
- pluggy: 1.0.0
- ply: 3.11
- polygraphy: 0.44.2
- pooch: 1.7.0
- portalocker: 2.7.0
- preshed: 3.0.8
- prettytable: 3.6.0
- prometheus-client: 0.16.0
- prompt-toolkit: 3.0.38
- protobuf: 3.20.3
- psutil: 5.9.4
- ptxcompiler: 0.7.0+27.gbcb4096
- ptyprocess: 0.7.0
- pure-eval: 0.2.2
- py-cpuinfo: 9.0.0
- pyarrow: 10.0.1.dev0+ga6eabc2b.d20230220
- pyasn1: 0.4.8
- pyasn1-modules: 0.2.8
- pybind11: 2.10.3
- pycocotools: 2.0+nv0.7.1
- pycparser: 2.21
- pydantic: 1.10.6
- pygments: 2.14.0
- pylibcugraph: 23.2.0
- pylibcugraphops: 23.2.0
- pylibraft: 23.2.0
- pynvml: 11.5.0
- pyopenssl: 23.1.1
- pyparsing: 3.0.9
- pyperclip: 1.8.2
- pyrootutils: 1.0.4
- pyrsistent: 0.19.3
- pysocks: 1.7.1
- pytest: 7.2.2
- pytest-rerunfailures: 11.1.2
- pytest-shard: 0.1.2
- pytest-xdist: 3.2.1
- python-dateutil: 2.8.2
- python-dotenv: 1.0.0
- python-hostlist: 1.23.0
- pytorch-fast-transformers: 0.4.0
- pytorch-lightning: 2.0.1.post0
- pytorch-quantization: 2.1.2
- pytz: 2022.7.1
- pyu2f: 0.1.5
- pyyaml: 6.0
- pyzmq: 25.0.1
- qtconsole: 5.4.2
- qtpy: 2.3.1
- raft-dask: 23.2.0
- readme-renderer: 37.3
- regex: 2022.10.31
- requests: 2.28.2
- requests-oauthlib: 1.3.1
- requests-toolbelt: 0.10.1
- resampy: 0.4.2
- responses: 0.18.0
- retry-decorator: 1.1.1
- rfc3986: 2.0.0
- rich: 13.3.4
- rmm: 23.2.0
- rotary-emb: 0.1
- rsa: 4.7.2
- scikit-learn: 1.2.0
- scipy: 1.6.3
- seaborn: 0.12.2
- secretstorage: 3.3.3
- send2trash: 1.8.0
- sentencepiece: 0.1.98
- sentry-sdk: 1.20.0
- setproctitle: 1.3.2
- setuptools: 65.5.1
- six: 1.16.0
- smart-open: 6.3.0
- smmap: 5.0.0
- sortedcontainers: 2.4.0
- soundfile: 0.12.1
- soupsieve: 2.4
- spacy: 3.5.1
- spacy-legacy: 3.0.12
- spacy-loggers: 1.0.4
- sphinx-glpi-theme: 0.3
- sqlalchemy: 2.0.10
- srsly: 2.4.6
- stack-data: 0.6.2
- stevedore: 5.0.0
- strings-udf: 23.2.0
- structured-kernels: 0.1.0
- sympy: 1.11.1
- tabulate: 0.9.0
- tbb: 2021.8.0
- tblib: 1.7.0
- tensorboard: 2.9.0
- tensorboard-data-server: 0.6.1
- tensorboard-plugin-wit: 1.8.1
- tensorrt: 8.5.3.1
- termcolor: 2.2.0
- terminado: 0.17.1
- thinc: 8.1.9
- threadpoolctl: 3.1.0
- thriftpy2: 0.4.16
- timm: 0.6.13
- tinycss2: 1.2.1
- tokenizers: 0.13.3
- toml: 0.10.2
- tomli: 2.0.1
- toolz: 0.12.0
- torch: 2.0.0a0+1767026
- torch-tensorrt: 1.4.0.dev0
- torchaudio: 2.0.1+3b40834
- torchmetrics: 0.11.4
- torchtext: 0.13.0a0+fae8e8c
- torchvision: 0.15.0a0
- tornado: 6.2
- tqdm: 4.65.0
- traitlets: 5.9.0
- transformer-engine: 0.6.0
- transformers: 4.28.1
- treelite: 3.1.0
- treelite-runtime: 3.1.0
- triton: 2.0.0.dev20221202
- twine: 4.0.2
- typer: 0.7.0
- types-dataclasses: 0.6.6
- typing-extensions: 4.5.0
- ucx-py: 0.30.0
- uff: 0.6.9
- urllib3: 1.26.14
- wandb: 0.15.1
- wasabi: 1.1.1
- wcwidth: 0.2.6
- webencodings: 0.5.1
- werkzeug: 2.2.3
- wheel: 0.38.4
- widgetsnbextension: 4.0.7
- xdoctest: 1.0.2
- xentropy-cuda-lib: 0.1
- xxhash: 3.2.0
- yacs: 0.1.8
- yarl: 1.9.1
- zict: 2.2.0
- zipp: 3.14.0
- zstandard: 0.21.0
* System:
- OS: Linux
- architecture:
- 64bit
- ELF
- processor: x86_64
- python: 3.8.10
- version: #1 SMP Debian 4.19.269-1 (2022-12-20)

### More info

_No response_

cc @awaelchli @morganmcg1 @borisdayma @scottire @parambharat

Start at the WandbLogger entry point and reproduce the issue with WandbLogger(config={'test_key': {'key2': 'test_value'}}), comparing it with the documented wandb.init(config=...) behavior. Done means nested configuration keys are formatted and searchable like test_key.key2 rather than stored as one dictionary-valued key.

Written by the indexing model from the issue text.